For purposes of the tightening or loosening of adjustment or fastening elements of ski shoes or ski bindings, screw drivers, coins or plate-like tools are used, which are introduceable into the slots of screw heads, adjustment elements or the like. Such small tools are often supplied with the ski equipment and may be stored in a small pocket provided for this purpose in the ski shoe or else the skier must carry them on his person. All such devices have the disadvantage that they may be lost, that they may fall into the snow during use thereof, or that they may simply be forgotten to be taken along.